From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D6C1C4332E for ; Thu, 19 Mar 2020 13:19:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C0A12098B for ; Thu, 19 Mar 2020 13:19:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584623941; bh=+pU4LulTU4mEYekBOst0ONklTIF3qN/8m0GK1PJ5h18=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eDLpWFUMH0RmHqYtMzk6d2Yx4wVMMU9VLmurksv8Eztns/3FW1kIjdqOJnvOxo4TD vtGIO9mAy+c4PqLVq8CRUZgolcVBt3iZRNF7tixS+Z07oL3MeHpQawpsKEvrFNUJny PeL4W/lWWbwi96LB4GYpBXEqPOxjkBOPMhi5+cco= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728944AbgCSNTA (ORCPT ); Thu, 19 Mar 2020 09:19:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:41718 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727731AbgCSNSy (ORCPT ); Thu, 19 Mar 2020 09:18:54 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A19E52098B; Thu, 19 Mar 2020 13:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584623934; bh=+pU4LulTU4mEYekBOst0ONklTIF3qN/8m0GK1PJ5h18=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vtQrYCAof7De8ao9pktjsSbj3zoaZPC4FoHKsSDhaTkZdTEUj4m0FxBb1/o1x6Inz JvYyDyOYIr3xDs24dcA7drSYu7MctR3IYlWVwdvMZgkngnax9zJ0sM+UtontbxuGr5 TrA7sJKZTw3k72Tqxcd2rB/pk6HPhb97DQTeaY2k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , John Soros , Sven Eckelmann , Simon Wunderlich Subject: [PATCH 4.14 76/99] batman-adv: Fix debugfs path for renamed hardif Date: Thu, 19 Mar 2020 14:03:54 +0100 Message-Id: <20200319124004.043668318@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123941.630731708@linuxfoundation.org> References: <20200319123941.630731708@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sven Eckelmann commit 36dc621ceca1be3ec885aeade5fdafbbcc452a6d upstream. batman-adv is creating special debugfs directories in the init net_namespace for each valid hard-interface (net_device). But it is possible to rename a net_device to a completely different name then the original one. It can therefore happen that a user registers a new net_device which gets the name "wlan0" assigned by default. batman-adv is also adding a new directory under $debugfs/batman-adv/ with the name "wlan0". The user then decides to rename this device to "wl_pri" and registers a different device. The kernel may now decide to use the name "wlan0" again for this new device. batman-adv will detect it as a valid net_device and tries to create a directory with the name "wlan0" under $debugfs/batman-adv/. But there already exists one with this name under this path and thus this fails. batman-adv will detect a problem and rollback the registering of this device. batman-adv must therefore take care of renaming the debugfs directories for hard-interfaces whenever it detects such a net_device rename. Fixes: 5bc7c1eb44f2 ("batman-adv: add debugfs structure for information per interface") Reported-by: John Soros Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/debugfs.c | 22 +++++++++++++++++++++- net/batman-adv/debugfs.h | 6 ++++++ net/batman-adv/hard-interface.c | 3 +++ 3 files changed, 30 insertions(+), 1 deletion(-) --- a/net/batman-adv/debugfs.c +++ b/net/batman-adv/debugfs.c @@ -18,6 +18,7 @@ #include "debugfs.h" #include "main.h" +#include #include #include #include @@ -338,7 +339,26 @@ out: } /** - * batadv_debugfs_del_hardif - delete the base directory for a hard interface + * batadv_debugfs_rename_hardif() - Fix debugfs path for renamed hardif + * @hard_iface: hard interface which was renamed + */ +void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface) +{ + const char *name = hard_iface->net_dev->name; + struct dentry *dir; + struct dentry *d; + + dir = hard_iface->debug_dir; + if (!dir) + return; + + d = debugfs_rename(dir->d_parent, dir, dir->d_parent, name); + if (!d) + pr_err("Can't rename debugfs dir to %s\n", name); +} + +/** + * batadv_debugfs_del_hardif() - delete the base directory for a hard interface * in debugfs. * @hard_iface: hard interface which is deleted. */ --- a/net/batman-adv/debugfs.h +++ b/net/batman-adv/debugfs.h @@ -31,6 +31,7 @@ void batadv_debugfs_destroy(void); int batadv_debugfs_add_meshif(struct net_device *dev); void batadv_debugfs_del_meshif(struct net_device *dev); int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface); +void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface); void batadv_debugfs_del_hardif(struct batadv_hard_iface *hard_iface); #else @@ -59,6 +60,11 @@ int batadv_debugfs_add_hardif(struct bat } static inline +void batadv_debugfs_rename_hardif(struct batadv_hard_iface *hard_iface) +{ +} + +static inline void batadv_debugfs_del_hardif(struct batadv_hard_iface *hard_iface) { } --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -1017,6 +1017,9 @@ static int batadv_hard_if_event(struct n if (batadv_is_wifi_hardif(hard_iface)) hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS; break; + case NETDEV_CHANGENAME: + batadv_debugfs_rename_hardif(hard_iface); + break; default: break; }